A novel sensitive, selective, and reversible tin(IV) ion optical sensor was prepared depends on the incorporation of amino-4-(3-nitrophenylazo)pyridine-3-ol, (ANPAP) and sodium tetraphenylborate (NaTPB) in a plasticised polyvinyl chloride (PVC) membranes containing dioctylsebacate (DOS) as a plasticiser. The influence of several parameters such as base matrix, pH, solvent mediator and reagent concentration were optimised. Comparison of the obtained results with previously reported methods indicated that the proposed procedure, in addition to fast and simplicity, provided good linear range (0.03–6.43 μmol L−1) and low detection limit (0.008 μmol L−1). Low detection and quantification limits, and excellent selectivity in presence of interfering ions as Cd2+ Zn2+, Hg2+, Fe3+, Cu2+, Ni2+, Ag+, Mn2+, Cr3+ and SO42− make it feasible to accurately and repeatedly monitor Sn4+ ions content in environmental samples with complicated matrices. The sensor was regenerated successfully using 0.2 mol L−1 of nitric acid solution while its response was reversible with the relative standard deviation (RSD) lower than 2.1% for seven replicate determinations of 4.0 μmol L−1 of Sn4+ in various membranes. The sensor was stable and stored for at least one month without observing any change in its sensitivity.